There are many types of blood processing and fluid exchange procedures, each providing different therapeutic effects and demanding different processing criteria. Typically, such procedures entail the removal of blood or another fluid from an individual and the return of blood or another fluid to the individual in a controlled fashion. Examples of such procedures include hemofiltration (HF), hemodialysis (HD), hemodialysis with hemofiltration (HDF), and peritoneal dialysis (PD).
In carrying out these procedures, specially designed fluid circuits, which can be complex and convoluted, are placed into a prescribed operative association with pumps, clamps, and sensors, which are typically mounted on a machine that is also specially designed to carry out the intended procedure. Numerous safety and control elements of the fluid circuit and the machine must be placed in operative association in order to carry out the procedure in the intended way. As a consequence, the process of loading a fluid circuit on the machine can be tedious and error-prone.
There is a need for simplicity and convenience when loading a fluid circuit in a prescribed way in association with safety and control elements on a blood and/or fluid processing machine.
Typically, when performing the blood processing and fluid exchange procedures of the type just described, a replacement or make-up fluid is returned back to the individual in some proportion to the amount of fluid that is removed from the individual. The type and make-up of fluids that these procedures handle vary according to the particular treatment modality being performed, e.g., among waste fluid and replacement fluid (in HF or HDF); or replacement fluid and dialysis solution (in HD or HDF); or fresh peritoneal dialysis solution and spent peritoneal dialysis solution (in PD. Controlled balancing of fluid amounts can be achieved by monitoring the weights of fluid removed and replacement or makeup fluid. However, weight sensing itself requires additional fluid circuit elements (e.g., weigh containers), additional hardware elements (e.g., weigh scales), as well as additional processing control and feedback features. These items add further complexity to the systems and their operation.
There is also a need for simplicity and convenience when undertaking a controlled balancing of fluids during a blood processing and/or fluid exchange procedure.